• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.107-110
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• 2002

The optical memory devices of BST thin films to composite $(Ba_{0.7}\;Sr_{0.3})TiO_{3}$ using sol-gel method were fabricated by changing of the depositing layer number on $Pt/Ti/SiO_{2}/Si$ substrate. The structural properties of optical memory devices to be ferroelectric was investigated by fractal analysis and 3-dimension image processing. The thickness of BST thin films at each coating numbers 3, 4 and 5 times was $2500[\AA]$, $3500[\AA]$ and $3800[\AA]$. BST thin films exhibited the most pronounced grain growth. The surface morphology image was roughness with coating numbers. The thin films increasing with coating numbers shows a more textured and complex configuration.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.269-274
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• 1999

As the semiconductor industry enters the next century, we are facing to the technological changes and challenges. Optical lithography has driven by the miniaturisation of semiconductor devices and has been accompanied by an increase in wafer productivity and performance through the reduction of the IC image geometries. In the last decade, DRAM(Dynamic Random Access Memories) have been quadrupoling in level of integration every two years. Korean chip makers have been produced the memory devices, mainly DRAM, which are the driving force of IC＇s(Integrated Circuits) development and are the technology indicator for advanced manufacturing. Therefore, Korean chip makers have an important position to predict and lead the patterning technology. In this paper, we will be discussed the limitations of the optical lithography, such as KrF and ArF. And, post optical lithography technology, such as E-beam lithography, EUV and E-beam Projection Lithography shall be introduced.

• Applied Microscopy
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• 제29권4호
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• pp.493-498
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• 1999

기억저장매체로서 광디스크의 개발이 활발히 진행되고 있으며 최근의 레이저 기술의 발전, 제조기술의 발전에 따른 기억밀도의 증가로서 기존의 자기기록매체와 경쟁을 하고 있다. 기록밀도의 증대와 신뢰성의 향상을 위하여 다층박막 구조를 가지는 광디스크의 미세구조는 더욱 복잡하며 소형화되고 있다. 이종의 물질로 구성된 다층박막형 광디스크의 미세구조 관찰 및 분석을 위해서는 투과전자현미경과 같은 미소영역 분석법이 필수적이며 비교적 간단하고 신뢰성 높은 시편준비법의 확립이 선행되어야 한다. 본 연구에서는 투과전자현미경 분석을 위한 광디스크의 평면 및 단면시료 제작법을 제시하고 제조된 시편으로부터 얻어진 광디스크의 미세구조 분석결과를 보고한다.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2001년도 학술대회지
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• pp.26-26
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• 2001

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.582-587
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• 2002

Current information storage devices, such as HDD, CD/DVD-ROM/RW, probe-based memory and hologram memory, are compared with biological information storage mechanisms in DNA and brain memory. Newly developed approaches to overcome the limit of storage capacity are introduced in both magnetic and optical recording devices. Linear and areal density of information stored in the biological and mechanical storages are compared for the applications and developments of new storage devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.278-278
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• 2016

Solution-processed metal-oxide semiconductors have been considered as the next generation semiconducting materials for transparent and flexible electronics due to their high electrical performance. Moreover, since the oxide semiconductors show high sensitivity to light illumination and possess persistent photoconductivity (PPC), these properties can be utilized in realizing optical memory devices, which can transport information much faster than the electrons. In previous works, metal-oxide semiconductors are utilized as a memory device by using the light (i.e. illumination does the "writing", no-gate bias recovery the "reading" operations) [1]. The key issues for realizing the optical memory devices is to have high photoconductivity and a long life time of free electrons in the oxide semiconductors. However, mono-layered indium-zinc-oxide (IZO) and mono-layered indium-gallium-zinc-oxide (IGZO) have limited photoconductivity and relaxation time of 570 nA, 122 sec, 190 nA and 53 sec, respectively. Here, we boosted up the photoconductivity and relaxation time using a double-layered IZO/IGZO active layer structure. Solution-processed IZO (top) and IGZO (bottom) layers are prepared on a Si/SiO2 wafer and we utilized the conventional thermal annealing method. To investigate the photoconductivity and relaxation time, we exposed 9 mW/cm2 intensity light for 30 sec and the decaying behaviors were evaluated. It was found that the double-layered IZO/IGZO showed high photoconductivity and relaxation time of 28 uA and 1048 sec.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.124-127
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• 2005

Rewritable optical memory devices such as an CD-RW and DVD+RW are data storage media, which take advantage of the different optical properties in the amorphous and crystalline states of phase change materials. The switching property, structural transformation, transformation kinetics and chemical bindings of $Ge_xSb_{100-x}$($6{\le}x{\le}$34) were studied to investigate the feasibility of applying $Ge_xSb_{100-x}$ alloys in optical memory. The $Ge_xSb_{100-x}$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, inductively coupled plasma atomic emission spectrometer (ICP-AES) and atomic force microscopy (AEM). Optimum fiim composition of $Ge_xSb_{100-x}$ was studied and its minimum time fur laser induced crystallization and optical contrast fur phase transition was performed. These results might be correlated with the binding energies between Ge and Sb, and indicate that $Ge_xSb_{100-x}$ have an potential far optical memory applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.79-79
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• 2013

Quantum-structures with nanoparticles have been attractive for various electronic and photonic devices [1,2]. In recent, nonvolatile memories such as nano-floating gate memory (NFGM) and resistance random access memory (ReRAM) have been studied using silicides, metals, and metal oxides nanoparticles [3,4]. In this study, we fabricated nonvolatile memories with silicides (WSi2, Ti2Si, V2Si) and metal-oxide (Cu2O, Fe2O3, ZnO, SnO2, In2O3 and etc.) nanoparticles embedded in polyimide matrix, and photovoltaic device also with SiC nanoparticles. The capacitance-voltageand current-voltage data showed a threshold voltage shift as a function of write/erase voltage, which implies the carrier charging and discharging into the metal-oxide nanoparticles. We have investigated also the electrical properties of ReRAM consisted with the nanoparticles embedded in ZnO, SiO2, polyimide layer on the monolayered graphene. We will discuss what the current bistability of the nanoparticle ReRAM with monolayered graphene, which occurred as a result of fully functional operation of the nonvolatile memory device. A photovoltaic device structure with nanoparticles was fabricated and its optical properties were also studied by photoluminescence and UV-Vis absorption measurements. We will discuss a feasibility of nanoparticles to application of nonvolatile memories and photovoltaic devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.67-67
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• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.657-657
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• 2013

In-situ observations of nano-scale behavior of nanomaterials are very important to understand onthe nano-scale phenomena associated with phase change, atomic movement, electrical or optical properties, and even reactions which take place in gas or liquid phases. We have developed on the in-situ experimental technologies of nano-materials (nano-cluster, nanowire, carbon nanotube, and graphene, et al.) and their interactions (percolation of metal nanoclusters, inter-diffusion, metal contacts and phase changes in nanowire devices, formation of solid nano-pores, melting behavior of isolated nano-metal in a nano-cup, et al.) by nano-discovery membrane platform [1-4]. Between two microelectrodes on a silicon nitride membrane platform, electrical percolations of metal nano-clusters are observed with nano-structures of deposited clusters. Their in-situ monitoring can make percolation devices of different conductance, nanoclusters based memory devices, and surface plasmonic enhancement devices, et al. As basic evidence on the phase change memory, phase change behaviors of nanowire devices are observed at a nano-scale.